1. Technical Field
The present invention relates to a game ball having radar reflectivity.
2. Related Art
There seems to be no end to unhappy automobile accidents caused by a child bursting into a road while engrossed in chasing a rolling game ball. The number of these accidents can be reduced by making the ball easier to be perceived earlier by the driver, even in dark roads, by imparting the surface of the ball with optical reflectivity and/or fluorescence, thus causing the ball to stand out in the light projected by headlights. Relying only on visual perception by the driver, however, is problematic in that seeing the ball is difficult when the latter is not far enough away and/or when visibility is poor.
Vehicle-onboard radars developed in recent years are being installed in ever more automobiles. Imparting radar reflectivity to a game ball allows the ball to be detected from far enough away by the vehicle-onboard radar of a running automobile when a game ball rolls into a poor-visibility road such as an alley and the like. The radar cross section afforded by just making the surface of the ball conductive, however, is small, and thus hard to detect by a vehicle-onboard radar. It is therefore necessary to provide the game ball with a large enough radar cross section. However, no game balls having a sufficiently large radar cross section, easy to detect by vehicle-onboard radars, have been known thus far.
Meanwhile, Japanese Patent Application Laid-open No. 2000-280980, for instance, discloses a rescue implement for vessels, comprising a black ball having a built-in reflector of large radar cross section. This conventional technology, however, is a rescue implement for vessels, which is a different technical field from game balls.